The ACLU hired Next Generation Public Affairs, a governmental affairs and public relations firm co-founded by Brady and Matt Strawn, former chairman of the Iowa Republican Party. Brady said he will act as a lobbyist and consultant for the same-sex marriage bill.

Brady said his job will to be lobby "Republicans and other like-minded folks, but primarily Republicans" in the House where a Senate-passed same-sex marriage bill remains stalled. "It's narrowly focused on the 10 or 11 (Republican lawmakers) who were open to the possibility of voting 'yes' on this," he said.

The pairing of the ACLU and a former state Republican chair might seem "unique," Brady said. But he noted the national ACLU in June hired Steve Schmidt, a veteran Republican adviser to presidents and presidential candidates, to spearhead a $10 million national effort to support same-sex marriage laws.

Brady acknowledged that some Republicans could feel at risk for casting a vote for the measure when lawmakers return to Springfield in the fall with the March primary looming.

He said the ACLU does not give money to candidates, but other groups backing same-sex marriage have pledged to support GOP lawmakers who vote for the measure in primary challenges.

"Nationally and Illinois, the point is, this is going to be the law," said Brady, who added he will register with the state as a lobbyist. "This is the direction things are going. I think a lot of people recognize that and want to be supportive of this."

It was Brady's personal support for passage of same-sex marriage legislation in Illinois that cost him the job as state GOP chairman in May amid opposition from social conservatives on the Republican State Central Committee.